Exploratory Data Analysis: PM2.5

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2017-12-25

ๆกˆไพ‹ไพ†ๆบ

Exploratory Data Analysis by Johns Hopkins University on Coursera

https://www.coursera.org/learn/exploratory-data-analysis

่ณ‡ๆ–™

ไธ‹่ผ‰่ณ‡ๆ–™

PM2.5

ๆณจๆ„

ไฝฟ็”จ readRDS() ๅ‡ฝๆ•ธ่ผ‰ๅ…ฅ่ณ‡ๆ–™

NEI <- readRDS("~/Downloads/exdata_NEI_data/summarySCC_PM25.rds")
SCC <- readRDS("~/Downloads/exdata_NEI_data/Source_Classification_Code.rds")

่ณ‡ๆ–™็š„ๅ‰ๅนพๅˆ—

head(NEI)
##     fips      SCC Pollutant Emissions  type year
## 4  09001 10100401  PM25-PRI    15.714 POINT 1999
## 8  09001 10100404  PM25-PRI   234.178 POINT 1999
## 12 09001 10100501  PM25-PRI     0.128 POINT 1999
## 16 09001 10200401  PM25-PRI     2.036 POINT 1999
## 20 09001 10200504  PM25-PRI     0.388 POINT 1999
## 24 09001 10200602  PM25-PRI     1.490 POINT 1999

่ฎŠๆ•ธ่ณ‡่จŠ

  • fips: A five-digit number (represented as a string) indicating the U.S. county
  • SCC: The name of the source as indicated by a digit string (see source code classification table)
  • Pollutant: A string indicating the pollutant
  • Emissions: Amount of PM2.5 emitted, in tons
  • type: The type of source (point, non-point, on-road, or non-road)
  • year: The year of emissions recorded

็ทด็ฟ’ๅ…งๅฎน

็ทด็ฟ’ไธ€

Have total emissions from PM2.5 decreased in the United States from 1999 to 2008? Make a plot showing the total PM2.5 emission from all sources for each of the years 1999, 2002, 2005, and 2008.

็ทด็ฟ’ไธ€ๅƒ่€ƒ่งฃ็ญ”

็ทด็ฟ’ไบŒ

Have total emissions from PM2.5 decreased in the Baltimore City, Maryland(fips == '24510') from 1999 to 2008? Make a plot answering this question.

็ทด็ฟ’ไบŒๅƒ่€ƒ่งฃ็ญ”

็ทด็ฟ’ไธ‰

Of the four types of sources indicated by the type(point, nonpoint, onroad, nonroad) variable, which of these four sources have seen decreases in emissions from 1999โ€“2008 for Baltimore City? Which have seen increases in emissions from 1999โ€“2008? Make a plot answer this question.

็ทด็ฟ’ไธ‰ๅƒ่€ƒ่งฃ็ญ”

็ทด็ฟ’ๅ››

Across the United States, how have emissions from coal combustion-related sources(SCC$EI.Sector) changed from 1999โ€“2008?

็ทด็ฟ’ๅ››ๅƒ่€ƒ่งฃ็ญ”

็ทด็ฟ’ไบ”

How have emissions from motor vehicle sources(SCC$EI.Sector) changed from 1999โ€“2008 in Baltimore City?

็ทด็ฟ’ไบ”ๅƒ่€ƒ่งฃ็ญ”

็ทด็ฟ’ๅ…ญ

Compare emissions from motor vehicle sources in Baltimore City with emissions from motor vehicle sources in Los Angeles County, California(fips == '06037'). Which city has seen greater changes over time in motor vehicle emissions?

็ทด็ฟ’ๅ…ญๅƒ่€ƒ่งฃ็ญ”